Patch "xfs: sanity check directory inode di_size" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    xfs: sanity check directory inode di_size

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfs-sanity-check-directory-inode-di_size.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From hch@lst.de  Thu Feb  2 11:14:03 2017
From: Christoph Hellwig <hch@lst.de>
Date: Thu,  2 Feb 2017 08:55:59 +0100
Subject: xfs: sanity check directory inode di_size
To: stable@vger.kernel.org
Cc: linux-xfs@vger.kernel.org, Amir Goldstein <amir73il@gmail.com>, "Darrick J. Wong" <darrick.wong@oracle.com>
Message-ID: <1486022171-8076-8-git-send-email-hch@lst.de>


From: Amir Goldstein <amir73il@gmail.com>

commit 3c6f46eacd876bd723a9bad3c6882714c052fd8e upstream.

This changes fixes an assertion hit when fuzzing on-disk
i_mode values.

The easy case to fix is when changing an empty file
i_mode to S_IFDIR. In this case, xfs_dinode_verify()
detects an illegal zero size for directory and fails
to load the inode structure from disk.

For the case of non empty file whose i_mode is changed
to S_IFDIR, the ASSERT() statement in xfs_dir2_isblock()
is replaced with return -EFSCORRUPTED, to avoid interacting
with corrupted jusk also when XFS_DEBUG is disabled.

Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/xfs/libxfs/xfs_dir2.c      |    3 ++-
 fs/xfs/libxfs/xfs_inode_buf.c |    7 +++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -631,7 +631,8 @@ xfs_dir2_isblock(
 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
 		return rval;
 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
-	ASSERT(rval == 0 || args->dp->i_d.di_size == args->geo->blksize);
+	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
+		return -EFSCORRUPTED;
 	*vp = rval;
 	return 0;
 }
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -386,6 +386,7 @@ xfs_dinode_verify(
 	struct xfs_inode	*ip,
 	struct xfs_dinode	*dip)
 {
+	uint16_t		mode;
 	uint16_t		flags;
 	uint64_t		flags2;
 
@@ -396,8 +397,10 @@ xfs_dinode_verify(
 	if (be64_to_cpu(dip->di_size) & (1ULL << 63))
 		return false;
 
-	/* No zero-length symlinks. */
-	if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0)
+	mode = be16_to_cpu(dip->di_mode);
+
+	/* No zero-length symlinks/dirs. */
+	if ((S_ISLNK(mode) || S_ISDIR(mode)) && dip->di_size == 0)
 		return false;
 
 	/* only version 3 or greater inodes are extensively verified here */


Patches currently in stable-queue which might be from hch@lst.de are

queue-4.9/xfs-don-t-rely-on-total-in-xfs_alloc_space_available.patch
queue-4.9/xfs-replace-xfs_mode_to_ftype-table-with-switch-statement.patch
queue-4.9/xfs-fix-bogus-minleft-manipulations.patch
queue-4.9/xfs-fix-cow-writeback-race.patch
queue-4.9/xfs-sanity-check-inode-mode-when-creating-new-dentry.patch
queue-4.9/xfs-extsize-hints-are-not-unlikely-in-xfs_bmap_btalloc.patch
queue-4.9/xfs-bump-up-reserved-blocks-in-xfs_alloc_set_aside.patch
queue-4.9/xfs-add-missing-include-dependencies-to-xfs_dir2.h.patch
queue-4.9/xfs-fix-bmv_count-confusion-w-shared-extents.patch
queue-4.9/xfs-adjust-allocation-length-in-xfs_alloc_space_available.patch
queue-4.9/xfs-verify-dirblocklog-correctly.patch
queue-4.9/xfs-fix-xfs_mode_to_ftype-prototype.patch
queue-4.9/xfs-clear-_xbf_pages-from-buffers-when-readahead-page.patch
queue-4.9/xfs-remove-racy-hasattr-check-from-attr-ops.patch
queue-4.9/xfs-make-the-assert-condition-likely.patch
queue-4.9/xfs-sanity-check-directory-inode-di_size.patch
queue-4.9/xfs-don-t-print-warnings-when-xfs_log_force-fails.patch
queue-4.9/xfs-don-t-wrap-id-in-xfs_dq_get_next_id.patch
queue-4.9/xfs-sanity-check-inode-di_mode.patch